Added day2

src/day2/1.rs

@@ -0,0 +1,44 @@
+#![feature(iterator_try_collect)]
+#![feature(test)]
+extern crate test;
+
+const INPUTS: [&str; 2] = [include_str!("./sample.txt"), include_str!("./input.txt")];
+
+fn parse(input: &'static str) -> Vec<Vec<i64>> {
+    input
+        .trim()
+        .lines()
+        .map(|line| {
+            line.splitn(3, 'x')
+                .map(|num| num.bytes().fold(0, |a, x| (a * 10) + (x - b'0') as i64))
+                .collect()
+        })
+        .collect()
+}
+
+fn solution(input: Vec<Vec<i64>>) -> i64 {
+    input.into_iter().fold(0, |a, c| {
+        let s1 = c[0] * c[1];
+        let s2 = c[1] * c[2];
+        let s3 = c[2] * c[0];
+
+        a + 2 * s1 + 2 * s2 + 2 * s3 + s1.min(s2.min(s3))
+    })
+}
+
+fn main() {
+    for input in INPUTS.iter() {
+        let output = parse(input);
+        let output = solution(output);
+        println!("{output}");
+    }
+}
+
+#[bench]
+fn solution_bench(b: &mut test::Bencher) {
+    b.iter(|| {
+        let input = parse(INPUTS[1]);
+        let result = solution(input);
+        test::black_box(result);
+    })
+}

src/day2/2.rs

@@ -0,0 +1,44 @@
+#![feature(iterator_try_collect)]
+#![feature(test)]
+extern crate test;
+
+const INPUTS: [&str; 2] = [include_str!("./sample.txt"), include_str!("./input.txt")];
+
+fn parse(input: &'static str) -> Vec<Vec<i64>> {
+    input
+        .trim()
+        .lines()
+        .map(|line| {
+            line.splitn(3, 'x')
+                .map(|num| num.bytes().fold(0, |a, x| (a * 10) + (x - b'0') as i64))
+                .collect()
+        })
+        .collect()
+}
+
+fn solution(input: Vec<Vec<i64>>) -> i64 {
+    input.into_iter().fold(0, |a, c| {
+        let s1 = 2 * (c[0] + c[1]);
+        let s2 = 2 * (c[1] + c[2]);
+        let s3 = 2 * (c[2] + c[0]);
+
+        a + c[0] * c[1] * c[2] + s1.min(s2.min(s3))
+    })
+}
+
+fn main() {
+    for input in INPUTS.iter() {
+        let output = parse(input);
+        let output = solution(output);
+        println!("{output}");
+    }
+}
+
+#[bench]
+fn solution_bench(b: &mut test::Bencher) {
+    b.iter(|| {
+        let input = parse(INPUTS[1]);
+        let result = solution(input);
+        test::black_box(result);
+    })
+}

src/day2/sample.txt

@@ -0,0 +1,2 @@
+2x3x4
+1x1x10